Aligning equals signs in latex

Hopefully someone here knows how to use latex, there are at least a few other math nerds. I'm doing my takehome test in latex because I haven't turned in shit for hw so far, let alone go to the class, and I need to impress the teacher.

I'm trying to align equals signs along the same vertical line, like you would do in showing the steps for evaluating something. All my googling tells me to use \begin{align} and \end{align} however, when I do that I get an error saying "environment align undefined". I try to google how to load a package or something that might have align in it, but no luck so far.